While delivery of the S-300 system to Syria had been suspended in 2013 following a request from Israel, Shoigu said: “Now, the situation has changed. And it’s not our fault.”

“In parts of the Mediterranean adjacent to Syria, there will be radio-electronic jamming of satellite navigation, onboard radars and communications systems used by military aircraft attacking targets in Syrian territory,” he said.

The downing reportedly occurred about 35 kilometres from the Syrian coast as the Ilyushin Il-20 aircraft was returning to Russia’s Hmeimim airbase near the north-western city of Latakia.

Russian Presidential spokesman Dmitry Peskov told state news agency Tass the missile systems were intended to protect the nation’s troops rather than act against third countries.

“It should be obvious to everyone that Russia’s actions aimed at ensuring security for its troops are necessary. This is why in this case, Russia is guided solely by these interests, these actions are not directed against third countries, they are meant to protect our own troops,” he said.

“… the situation concerning the safety of our troops, our pilots, which arose after this tragedy dictates the necessity to implement extra measures – effective and energetic measures.”

The missile systems, which would be delivered within two weeks, will also be able to track and identify Russian aircraft. Israel maintains that indiscriminate fire from Syrian forces caused the incident.